The present invention relates generally to operations performed and equipment utilized in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides systems and methods for controlling flow and access in multilateral completions.
Multilateral wells typically have one or more branch or xe2x80x9clateralxe2x80x9d wellbore branching off from a main or xe2x80x9cparentxe2x80x9d wellbore. An intersection between main and branch wellbores is known as a xe2x80x9cwellbore junction.xe2x80x9d Completion equipment positioned at a wellbore junction for controlling access and/or flow between the wellbores may also be referred to as a xe2x80x9cjunction.xe2x80x9d
Various methods of completing wellbore junctions provide for access and/or flow between the wellbores, but do not include provisions for remotely varying the rate of fluid produced from each of the wellbores. Other methods of completing wellbore junctions provide for remotely varying the rate of fluid produced from each of the wellbores, but do not permit access between the wellbores. In some such completions, the entire completion string must be retrieved from the well in order to gain access to the branch wellbore, or to the main wellbore below the junction.
In view of the above, it will be readily appreciated that it would be highly desirable to provide a method wherein flow and access are permitted between main and branch wellbores, and wherein a rate of fluid produced from each of the wellbores may be remotely regulated. It would also be desirable to provide completion apparatus which permits remotely operated flow control devices thereof to be retrieved from the well separate from the remainder of the junction. It would further be desirable to otherwise provide improved systems and methods for controlling flow and access in multilateral completions.
In carrying out the principles of the present invention, in accordance with particular embodiments thereof, systems and methods are provided for controlling flow and access in multilateral completions. These embodiments utilize multiple flow control devices to regulate flow between a tubular string and respective intersecting wellbores. The tubular string is engaged with a junction device, which provides separate passages for flow between the flow control devices and the respective wellbores.
In one aspect of the invention, a method of controlling flow in a well having intersecting first and second wellbores is provided. The method includes the steps of positioning a junction device in the well, the junction device having first and second flow passages formed therethrough, and engaging a tubular string with the junction device. The first flow passage communicates with an interior of the tubular string, and the second flow passage communicates with an annulus formed between the tubular string and the first wellbore, when the engaged tubular string and junction device are positioned in the well.
Fluid produced into the first wellbore through the first flow passage is flowed to an exterior of the tubular string, and then into the tubular string via a first flow control device. Fluid produced into the second wellbore is flowed through the second flow passage, then into the annulus, and then into the tubular string via a second flow control device.
In another aspect of the invention, another method of controlling flow in a well having intersecting first and second wellbores is provided. The method includes the steps of positioning a junction device in the well, the junction device having first and second flow passages formed therein, and engaging a tubular string with the junction device, the tubular string having a first flow control device interconnected therein operative to regulate flow between the first flow passage and an interior of the tubular string, and the tubular string having a second flow control device interconnected therein operative to regulate flow between the second flow passage and the tubular string interior. Fluid flowing between an interior of the tubular string and the first flow passage is isolated, external to the tubular string, from fluid flowing between the interior of the tubular string and the second flow passage.
In yet another aspect of the invention, a system for controlling flow in a well having an intersection between first and second wellbores is provided. The system includes a tubular string positioned in the first wellbore, the tubular string having first and second flow control devices interconnected therein. A junction device is engaged with the tubular string and has first and second flow passages therein.
The first flow passage provides fluid communication between the first flow control device and the first wellbore below the intersection. The second flow passage provides fluid communication between the second flow control device and the second wellbore below the intersection. A window is formed in the junction device, thereby providing access between the first and second flow passages.
In a further aspect of the invention, another system for controlling flow in a well having an intersection between first and second wellbores is provided. The system includes a junction device having first and second flow passages formed therein, the first flow passage being in fluid communication with the first wellbore below the intersection, and the second flow passage being in fluid communication with the second wellbore below the intersection. A tubular string has first and second flow control devices interconnected therein. The first flow control device regulates flow between the first flow passage and an interior of the tubular string. The second flow control device regulates flow between the second flow passage and the tubular string interior.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.